1. Field of the Invention
The invention disclosed herein relates generally to method and apparatus for thin film deposition on optical thin film substrates, semiconductor wafers, and magnetic storage devices. More particularly, this invention relates to an improved apparatus and method for more uniformly depositing thin films on semiconductor wafers with materials sputtered from targets by collision of high-energy ion beams.
2. Description of the Prior Art
Several difficulties have been encountered by those of ordinary skill in the art for applying conventional apparatuses and methods for carrying out the task of thin film deposition on substrates, such as the optical thin film and the semiconductor wafers. Specifically, even that the thin-film thickness may be critical for narrow band optical filters and integrated-circuit manufacture; a high degree of thin-film uniformity is not easily achievable. Furthermore, the uniformity of thin-film thickness is generally not measured and also difficult to control. Many methods and apparatuses have been employed to produce multiple layers of thin films in the processes of manufacturing semiconductor devices, dielectric filters, highly reflective mirrors, magnetic storage devices and other applications. A typical sputtering deposition system is contained in a vacuum chamber where a target material is impacted by ion beams to sputter material off the target by collision mechanisms. The sputtered material is deposited onto a substrate to form a thin film.
The conventional thin film deposition apparatuses can be applied for thin film deposition on a single or multiple substrates. The single substrate thin-film deposition system typically provides a rotational carrier to rotate the single substrate along a rotational axis while the target materials are sputtering onto the surface of the substrate to uniformly deposit the thin film on surface of the rotating substrate. For a multiple substrate deposition system, a common rotational carrier is used that has several single substrate holders. The common carrier is rotating along a central axis while each substrate holder is also rotating each single substrate along a holder axis such that the thin-film may be uniformly deposited onto several substrates because every part of these substrates would have equal time of deposition time for thin-film deposition during these rotation movements. However, as a more stringent requirement is imposed on the thickness-uniformity, the conventional methods of deposition are often unable to satisfy a reduced tolerance limit of the film-thickness variances. Furthermore, a technique to monitor and control the deposition process to achieve a predefined requirement of thickness uniformity is not available. The state of the art in film deposition technology thus limits a person of ordinary skill in the art to achieve higher thickness uniformity when systems and methods currently available are applied to carry out the thin-film deposition processes.
For the above reasons, a need still exists in the art of thin-film deposition to provide a new and improved apparatus and method for improving the uniformity in thin film deposition. A method to monitor and control the deposition process to improve the thickness uniformity is also required to overcome the limitations and difficulties faced by the traditional techniques of thin film deposition.
It is the object of the present invention to provide a new system configuration and method for carrying out the thin film deposition process by monitoring and more precisely control the motion of the substrates for thin film deposition. Specifically, it is the object of the present invention to present a new system configuration of thin film deposition by moving the substrates in rotational and lateral movements. The speed of the lateral movement is further controlled by applying the measurements of thin-film thickness to assure high uniformity of thin-film thickness is achieved by changing the speed of the lateral movements depending on the thickness measurements. With the new and improved system configuration and method of operations, the difficulties of the prior art systems and methods are resolved. More uniform thin films have been produced for optical filter manufacture and IC device manufacture.
A thin film deposition apparatus and method are disclosed in this invention. The method includes a step of providing a vacuum chamber for containing a thin-film particle source for generating thin-film particles to deposit a thin-film on the substrates. The method further includes a step of containing a substrate holder in the vacuum chamber for holding a plurality of substrate having a thin-film deposition surface facing the thin-film particle source. The method further includes a step of providing a rotational means for rotating the substrate holder to rotate each of the substrates exposed to the thin-film particles for depositing a thin film thereon. And, the method further includes a step of providing a laterally moving means for laterally moving and controlling a duration of exposure time across a radial direction for each of the substrates for controlling a thickness uniformity of the thin-film deposited on each of the substrates.
A preferred embodiment of this invention discloses a thin film deposition apparatus for performing a thin-film deposition on a plurality of semiconductor substrates. The apparatus includes a vacuum chamber containing a thin-film particle source for generating thin-film particles to deposit a thin-film won the substrates. The apparatus further includes a substrate holder disposed in the vacuum chamber for holding a plurality of substrate each having a thin-film deposition surface facing the thin-film particle source. The apparatus further includes a rotational means for rotating the substrate holder to rotate each of the substrates exposed to the thin-film particles for depositing a thin film thereon. The apparatus further includes a laterally moving means for laterally moving the substrate holder and controlling a duration of thin-film particle exposure time across a radial direction for each of the substrates for controlling a thickness uniformity of the thin-film deposited on each of the substrates.
These and other objects and advantages of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiment which is illustrated in the various drawing figures.